428 or 520 sprockets, which last longer
 

The Lifan 200 has 428, the Roketa (Zong) 200 has 520. It would be handy to have the same size on both so I could carry just 1 spare master link and section of chain in the tool kit I swap between bikes. Does anyone have evidence that 520 sprockets last longer than 428 or vice versa?

I would think from an engineering stand point that 520 will outlast 428... larger rollers, more surface area, not to mention thicker stronger links and side plates.... I converted my shineray to 520 for the ninja wheel supermoto conversion and I have put 1000 miles on and theres not any visible wear yet....there was visible wear on my old 428 sprockets after the 500 miles I put on em after gearing up from stock...

It only makes sense that the 520 would outlast the 428, but I also suspect that a 520 would be a larger parasitic power loss.

I also suspect the 520 chain and sprockets will wear slower than the 428 chain and sprockets. ;) In addition, you will have a much larger selection of 520 drive chains from which to choose, at more competitive prices. :)